Re-torqueing exhaust header bolts / potential for exhaust gasket leaks?

[facultyofmusic]

Just installed the gen3 coyote along with the DS exhaust headers. Used FFR provided gasket and stage 8 locking bolts and torqued it to something like 24lbs (couldn't fit a torque wrench down there). After the installation I decided to read more about what people did after and I read a lot about heat cycling and re-torqueing the bolts. My question is, how the heck would you re-torque the bolts after the engine is in and everything else installed for the first few starts? If I don't do this, will the exhaust header eventually leak? If there is a leak, how can you tell, and what can you do aside from taking the engine back out completely?

I have a vague understanding of head-cycling and how heat-expansion causes some things to loosen up, but not much concrete ideas. Any knowledge and advice would be awesome.

[edwardb]

I haven't had any issues with the exhaust header bolts loosening on either Coyote builds I've done. I use Remflex gaskets. But that's a preference and no reason to think the gaskets you use won't also hold up just fine. Leaks are typically detectible by sound or in the case of the Coyote with O2 sensors it might throw codes if the air-fuel mixture is affected. Sounds like you've installed the headers correctly with decent parts. I wouldn't worry about it. Just keep an eye on it like you will most everything once you start driving. I don't understand how an issue would cause you to take the engine out completely. You have to remove the headers to do that, so kind of self-defeating to start with. Agreed several of the bolts are hard to get to. But they're all eventually doable with the engine in place.

[Madfor67]

You can reach most of the bolts using an elbow and a long extensions. In fact, I replaced BBK short headers with Gas-N headers on my Coyote with everything in place. Took a few days, but possible with the right tools. I re-torqued them 3 times after heat cycles with everything in place as well. I put a dab of permatex copper gasket sealant on the bolts on my 3rd and last retorquing.

[facultyofmusic]

Hmm, perhaps I've just been traumatized by how much effort it took to get it on while the engine is still in midair. I guess I'll see how it goes once the thing starts up.

[mburger]

You used Stage 8 bolts. How could they ever need re-torquing? Perhaps I missed something obvious. (It’s happened before!)

[Al_C]

I'm with Mark on this one. If you used stage 8 bolts with the locking tabs, you won't have any issues.

[nuhale]

I just swapped out my Gen2 header bolts to stage 8 a week ago. I was able to do so and torque them to spec from under the car. There are a couple are are very difficult on the DS but was able to get to it with some extensions, crows feet, universal socket joints etc. A little bit of blood, sweat and surgical precision and got them torqued down and locked in. Hope to not deal with this ever again.

[RoadRacer]

I'm with Mark on this one. If you used stage 8 bolts with the locking tabs, you won't have any issues.

dang, even as old as I am, I'm still learning something every day :)

Never seen or heard of those, but sure as hell got some on order now! Thanks.

[facultyofmusic]

If I'm wrong someone PLEASE correct me:
Based on my (very limited) understanding the reason for "re-torquing" the bolts isn't that they spin loose during the first few heat cycles, but because the gasket expands/contracts/moves-around a lot and it needs to "settle in". During this process it's wise to re-torque the header bolts to really tighten it down after it settles.

[mburger]

dang, even as old as I am, I'm still learning something every day :)

Never seen or heard of those, but sure as hell got some on order now! Thanks.

There are other types out there as well. I’ve had to install and remove them multiple times for various reasons and I’ve hung over the fenders cussing up a storm. They absolutely work, but aren’t the easiest to install or remove.

[RoadRacer]

There are other types out there as well. I’ve had to install and remove them multiple times for various reasons and I’ve hung over the fenders cussing up a storm. They absolutely work, but aren’t the easiest to install or remove.

Thanks.. one advantage of a fenderless 33 ;)

[toadster]

If I'm wrong someone PLEASE correct me:
Based on my (very limited) understanding the reason for "re-torquing" the bolts isn't that they spin loose during the first few heat cycles, but because the gasket expands/contracts/moves-around a lot and it needs to "settle in". During this process it's wise to re-torque the header bolts to really tighten it down after it settles.

I think you'll be ok - the amount of 'spin' on those bolts probably wouldn't equate to any gasket 'squish' through heat cycling - I'd say you're good, the Stage8's are nice!